- 根目录:
- drivers
- clk
- samsung
- clk.c
/*
* Copyright (c) 2013 Samsung Electronics Co., Ltd.
* Copyright (c) 2013 Linaro Ltd.
* Author: Thomas Abraham <thomas.ab@samsung.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This file includes utility functions to register clocks to common
* clock framework for Samsung platforms.
*/
#include <linux/syscore_ops.h>
#include "clk.h"
static DEFINE_SPINLOCK(lock);
static struct clk **clk_table;
static void __iomem *reg_base;
#ifdef CONFIG_OF
static struct clk_onecell_data clk_data;
#endif
#ifdef CONFIG_PM_SLEEP
static struct samsung_clk_reg_dump *reg_dump;
static unsigned long nr_reg_dump;
static int samsung_clk_suspend(void)
{
struct samsung_clk_reg_dump *rd = reg_dump;
unsigned long i;
for (i = 0; i < nr_reg_dump; i++, rd++)
rd->value = __raw_readl(reg_base + rd->offset);
return 0;
}
static void samsung_clk_resume(void)
{
struct samsung_clk_reg_dump *rd = reg_dump;
unsigned long i;
for (i = 0; i < nr_reg_dump; i++, rd++)
__raw_writel(rd->value, reg_base + rd->offset);
}
static struct syscore_ops samsung_clk_syscore_ops = {
.suspend = samsung_clk_suspend,
.resume = samsung_clk_resume,
};
#endif /* CONFIG_PM_SLEEP */
/* setup the essentials required to support clock lookup using ccf */
void __init samsung_clk_init(struct device_node *np, void __iomem *base,
unsigned long nr_clks, unsigned long *rdump,
unsigned long nr_rdump, unsigned long *soc_rdump,
unsigned long nr_soc_rdump)
{
reg_base = base;
#ifdef CONFIG_PM_SLEEP
if (rdump && nr_rdump) {
unsigned int idx;
reg_dump = kzalloc(sizeof(struct samsung_clk_reg_dump)
* (nr_rdump + nr_soc_rdump), GFP_KERNEL);
if (!reg_dump) {
pr_err("%s: memory alloc for register dump failed\n",
__func__);
return;
}
for (idx = 0; idx < nr_rdump; idx++)
reg_dump[idx].offset = rdump[idx];
for (idx = 0; idx < nr_soc_rdump; idx++)
reg_dump[nr_rdump + idx].offset = soc_rdump[idx];
nr_reg_dump = nr_rdump + nr_soc_rdump;
register_syscore_ops(&samsung_clk_syscore_ops);
}
#endif
clk_table = kzalloc(sizeof(struct clk *) * nr_clks, GFP_KERNEL);
if (!clk_table)
panic("could not allocate clock lookup table\n");
if (!np)
return;
#ifdef CONFIG_OF
clk_data.clks = clk_table;
clk_data.clk_num = nr_clks;
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
#endif
}
/* add a clock instance to the clock lookup table used for dt based lookup */
void samsung_clk_add_lookup(struct clk *clk, unsigned int id)
{
if (clk_table && id)
clk_table[id] = clk;
}
/* register a list of aliases */
void __init samsung_clk_register_alias(struct samsung_clock_alias *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
if (!clk_table) {
pr_err("%s: clock table missing\n", __func__);
return;
}
for (idx = 0; idx < nr_clk; idx++, list++) {
if (!list->id) {
pr_err("%s: clock id missing for index %d\n", __func__,
idx);
continue;
}
clk = clk_table[list->id];
if (!clk) {
pr_err("%s: failed to find clock %d\n", __func__,
list->id);
continue;
}
ret = clk_register_clkdev(clk, list->alias, list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
/* register a list of fixed clocks */
void __init samsung_clk_register_fixed_rate(
struct samsung_fixed_rate_clock *list, unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_fixed_rate(NULL, list->name,
list->parent_name, list->flags, list->fixed_rate);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(clk, list->id);
/*
* Unconditionally add a clock lookup for the fixed rate clocks.
* There are not many of these on any of Samsung platforms.
*/
ret = clk_register_clkdev(clk, list->name, NULL);
if (ret)
pr_err("%s: failed to register clock lookup for %s",
__func__, list->name);
}
}
/* register a list of fixed factor clocks */
void __init samsung_clk_register_fixed_factor(
struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_fixed_factor(NULL, list->name,
list->parent_name, list->flags, list->mult, list->div);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(clk, list->id);
}
}
/* register a list of mux clocks */
void __init samsung_clk_register_mux(struct samsung_mux_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_mux(NULL, list->name, list->parent_names,
list->num_parents, list->flags, reg_base + list->offset,
list->shift, list->width, list->mux_flags, &lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(clk, list->id);
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
}
/* register a list of div clocks */
void __init samsung_clk_register_div(struct samsung_div_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
if (list->table)
clk = clk_register_divider_table(NULL, list->name,
list->parent_name, list->flags,
reg_base + list->offset, list->shift,
list->width, list->div_flags,
list->table, &lock);
else
clk = clk_register_divider(NULL, list->name,
list->parent_name, list->flags,
reg_base + list->offset, list->shift,
list->width, list->div_flags, &lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(clk, list->id);
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
}
/* register a list of gate clocks */
void __init samsung_clk_register_gate(struct samsung_gate_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_gate(NULL, list->name, list->parent_name,
list->flags, reg_base + list->offset,
list->bit_idx, list->gate_flags, &lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
samsung_clk_add_lookup(clk, list->id);
}
}
/*
* obtain the clock speed of all external fixed clock sources from device
* tree and register it
*/
#ifdef CONFIG_OF
void __init samsung_clk_of_register_fixed_ext(
struct samsung_fixed_rate_clock *fixed_rate_clk,
unsigned int nr_fixed_rate_clk,
struct of_device_id *clk_matches)
{
const struct of_device_id *match;
struct device_node *np;
u32 freq;
for_each_matching_node_and_match(np, clk_matches, &match) {
if (of_property_read_u32(np, "clock-frequency", &freq))
continue;
fixed_rate_clk[(u32)match->data].fixed_rate = freq;
}
samsung_clk_register_fixed_rate(fixed_rate_clk, nr_fixed_rate_clk);
}
#endif
/* utility function to get the rate of a specified clock */
unsigned long _get_rate(const char *clk_name)
{
struct clk *clk;
unsigned long rate;
clk = clk_get(NULL, clk_name);
if (IS_ERR(clk)) {
pr_err("%s: could not find clock %s\n", __func__, clk_name);
return 0;
}
rate = clk_get_rate(clk);
clk_put(clk);
return rate;
}